Locking type tongs



Apnl 5, 1955 A. BARCHOFF LOCKING TYPE TONGS 2 Sheets-Sheet .1

Filed Sept. 25, 1952.

INVENTOR ATTORNEY April 5, 1955 A. BARCHOFF 2,705,659

LOCKING TYPE TONGS Filed Sept. 23, l952 2 Sheets-Sheet 2 ATTORNEY UnitedStates Patent I O LOCKING TYPE TONGS Abraham Barchotf, New York, N. Y.,assignor to Eastern Brass & Copper Co., Inc., New York, N. Y., acorporation of New York Application September 23, 1952, Serial No.311,033

1 Claim. (Cl. 294118) This invention relates to lifting and loweringtongs and more particularly to tongs capable of being locked in theoperative position thereof to maintain engagement with the load beinghandled thereby.

It is the object of the present invention to provide a tong device whichis rugged and simple in construction and reliable in operation.

It is a further object of the invention to provide for the locking oftongs of the crossed-lever type in the operative position thereof, inorder to maintain the grip of the object being handled while the tongsare manipulated into different positions, and which would normallyresult in the release of the object therefrom. The adaptation ofconventional tongs to locking type tongs in accordance with the instantinvention requires but the addition of a few simple parts which may beadded to existing tong devices or which may be incorporated as parts ofnew tong assemblies.

The invention proceeds upon the principle of adding to a tong device ofthe crossed-lever type a cross-arm or bracing arm extending between thepivotal mountings of the crossed levers remote from the gripping jaws.The cross-arm may be provided with an opening at one end which fixes thelocation of one of the pivotal mountings and is provided with alongitudinal slot at the opposite end thereof to permit the tong leversto execute the necessary" movements attendant the gripping and releasingof objects by the gripping jaws in dependence upon the degree of openingof the jaws. The end of the cross-arm adjacent to the longitudinal slotis provided with threads along opposed edges thereof for the guidance ofan interiorly threaded locking nut which cooperates with the threads onthe cross-arm to permit the locking npt to be brought into juxtapositionwith the relativelyfnovable pivotal mounting of the tongs in theoperative, position of the tong device. Thus, the locking nut pre'yentsa spreading movement of the tongs while the tongs and the load engagedthereby are manipu lated in the course of diverse transporting andhandling operations.

Other objects and purposes will appear from the following detaileddescription of the invention taken in conjunction with the accompanyingdrawings, wherein Fig. 1 is a front elevation of the tong device inaccordance with the present invention;

Fig. 2 is a left end view of Fig. 1;

Fig. 3 is a front elevation of the tong device illustrating itsmanipulation in the course of engagement thereof with a crate of metal;

Fig. 4 is a sectional view along line 44 of Fig. 3; and

Fig. 5 is a vertical sectional view along line 5-5 of Pi 4.

The drawings illustrate a tong device of the crossedlever type which maybe of conventional design by its provision of crossed levers 1, 1 havinggripping jaws or points 3, 3' seated in the opposed adjacent ends 2, 2',respectively. The levers are pivotally mounted to each other atintermediate parts thereof by bolt assembly 4, 4. The ends of levers 1,1 remote from the gripping jaws are pivotally mounted to the lower endsof crossed bars 6, 6', respectively, at pivotal mountings 5 and 15,respectively. The upper ends of bars 6, 6' are pivotally joined togetherby the common pivotal mounting 7, 7 which also carries the hook 9 forengagement with a chain hook H extending from a hoist, crane or thelike.

2,705,659 Patented Apr. 5, 1955 \s is well known in the art, the leversgenerally described above may be formed of dual assemblies of congruouslevers. For example, levers 1 may be formed of companion levers whichpivot between the more widely spaced congruous levers 1 and the pivotbolt assembly 4 includes the spacing sleeve 4 between the levers 1'.Likewise, the congruous straight bars 6 extend between levers 1 whilebars 6' are disposed on the outside of bars 6 as well as on the outsideof congruous levers 1 with the spacing sleeve 7' on the pivot assembly 7spanning the distance between the innermost bars 6.

The distance between the bars 6 at their lower ends and between thelevers 1' at their upper ends in Figs. 1 and 2 is spanned by a cross'arm10 which is provided with an opening at one end thereof to accommodatethe bolt 5 which pivotally integrates the levers 1 and 6 and lever 10.The opposite pivotal mounting of the levers, including the bolt 15, maymove relatively to bolt 5 by virtue of a slot 12 provided in thecross-arm 10 at the end thereof remote from the fixed pivotal mounting5. The movement of pivotal mounting 15 along the slot 12 of arm 10enables the tong device to operate in the conventional manner as thepivotal mountings 5 and 15 approach each other when the jaws approacheach other and recede from each other as the jaws are spread apart. Inthis case the cross-arm 10 merely functions as a bracing arm for thetong assembly.

In order to attain the advantages of the invention, the arm 10 isprovided with screw threads 11 on the upper and lower edges thereofadjacent to the slot 12 and an interiorly threaded locking collar 20 isthreaded upon the arm for rotary movement thereon in order to bring thelocking or blocking edge 22 of the collar into engagement with thepivotal mounting 15 of the tong device.

The arm 10 is preferably provided with a stop disk 13 which may bedetached from the arm in order to mount the locking collar 20 on the arm10. The disk 13 may be attached to the arm by means of screw bolt 14cooperating with a threaded opening in the end of arm 10 to fix the stop13 at the end of arm 10, which prevents a complete disengagement of thelocking collar from the arm after the collar has been mounted thereon.

With the locking arm 20 in its fully withdrawn position as shown in Fig.1, the tongs may execute its normal movements as controlled by thelifting; of the tongs at hook 9 and the engagement of any object withthe gripping jaws 3, 3'. In order to prevent a release of the object bythe gripping jaws following the grasping thereof, if the object requiresadditional manipulations around a plant, as might be the case in thehandling of heavy crates of sheet metal, the locking nut 20 is advancedupon the arm 10 until the edge 20 is forced into close abutting relationwith the pivotal mounting 15. This prevents an opening movement of thecrossed-lever system and correspondingly of the gripping jaws, despite arelease of the book 9 by the hoisting cable or other granigulationsexecuted with the load as indicated in The rotation of the locking nutis facilitated by making the same of substantial diameter and byproviding circumferential cutouts 21 therein for the purpose offacilitating a convenient hand-hold thereof.

Following the positioning of the load L, as shown in Fig. 3, in anydesired position, the locking nut 20 may be retracted along the arm 10in order to permit the spreading of the jaws and the release of theload.

The objectives of the instant invention may be attained by the provisionof a more complex assembly in which the cross-arm may be provided with apair of slots for guiding the relative movements of the pivotalmountings and which embodies a screw threaded locking nut at each endfor blocking the levers against spreading movement in the operativeposition of the tong device.

While I have described my invention as embodied in a specific form andas operating in a specific manner for purposes of illustration, itshould be understood that I do not limit my invention thereto, sincevarious modifications will suggest themselves to those skilled in theart without departing from the spirit of my invention, the scope ofwhich is set forth in the annexed claim.

I claim:

A tong device comprising a pair of crossed pivoted levers terminating ingripping jaws at opposed adjacent ends thereof, intersecting pivotedbars connected to the opposite ends of said levers forming pivotalmountings therebetween which are relatively movable with respect to eachother, an arm interconnecting said pivotal mountings, one of which isfixedly disposed at one end of said 10 arm, said arm having a slot foraccommodating the instantaneous movement of the other one of saidpivotal mountings during the contracting and distending movements ofsaid jaws, screw threads disposed on the exterior -thereon forengagement with and blocking said lastmentioned pivotal mounting in thecontracted position 5 of said jaws.

References Cited in the file of this patent UNITED STATES PATENTS1,877,975 Robb Sept. 20, 1932 2,476,169 White et al. July 12, 1949FOREIGN PATENTS 43,589 Norway Jan. 17, 1927

